Machine Type Communications (MTC) devices, sometimes also referred to as Machine-to-Machine (M2M) devices, are increasingly being used for a variety of applications. MTC is a form of data communication which involves one or more entities that do not necessarily need human interaction. In a wireless communication system, the number of MTC devices may be several orders of magnitude greater than ‘traditional’ devices. Many MTC devices will be relatively stationary and/or generate low volumes of traffic. Others, however, may be relatively mobile and may have the capability to generate normal quantities of signalling.
In the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) standard, support for MTC devices was introduced in release 9. Details of MTC devices as applied to LTE are given in the 3GPP standard TS22.368. In this context, the total signalling related to mobility and connection management for large numbers of MTC User Equipment (UE) is of potential concern in at least two situations:
when an application (running on both an application server and many MTC devices at the same time) makes a request to “do something” via paging messages;
when many MTC devices are roaming into a new Tracking Area (TA), and they need to perform a TA update, or be handed over to a new base station (known in LTE as an Evolved Node B, and abbreviated as eNodeB or eNB).
In addition, power consumption is of concern for many MTC devices. Based on current 3GPP standards, it consumes a significant amount of power for a UE to maintain connection with an eNB, either camping on or staying in connected mode. On the other hand, it takes a long time and also consumes a significant amount of power if the UE has to switch between idle mode and connected mode.
Accordingly, it is desirable to enable sufficient mobility and connection management without overloading the network and with lower power consumption.